A filter is known from WO 2013 024105 A1 for the de-oiling of air originating from an air compressor or a vacuum pump. In this filter, a sealing connection between the pleated filters and a U-shaped groove of a cover element of the filter is produced through the use of an adhesive or a sealant. However, the use of adhesives for fixing the pleated filters is expensive and additionally problematic due to the partial uncertainty of the chemical and thermal stability.
Another filter insert is known from WO 96 28238 A1. In this filter element, a pleated filter wound on a support tube is connected by means of a flange connection or flanging with a mounting flange of the filter housing. A flange is understood here as a connection which is produced through right-angle bending of an edge of a round or oval metal sheet. The flange connection known from WO 96 28238 A1 enables the omission of an adhesion of the pleated filter on the end faces of the filter element. In order to produce this flange connection, a flange ring is arranged in the end region of the air de-oiling element. This flange ring is a separate element which is not integrated in the end face cover element of the filter element. The flange ring itself is not flanged, but rather serves as a counter support for a bead introduced in the mounting flange and the support tube.